1. Field of the Invention
The disclosed invention relates to ignition systems in general, and particularly to ignition systems as applied to internal combustion engines. More specifically, it relates to an ignition system for a piston type internal combustion engine as contrasted with a turbine type of engine, and specifically to the distributor of the ignition system.
2. Description of the Prior Art
Existing art distributor type ignition systems for piston type internal combustion engines basically fall into the following two categories: (1) conventional distributors having a rotating conductor arm (rotor) which transmits voltage from the high voltage electrode of the ignition coil to the respective spark plug terminals via means of a rotating conductor which is in direct contact with the high voltage electrode of the ignition coil and is rotated in close proximity with each spark plug terminal to allow a voltage arc to occur between the rotating arm (rotor) and the terminal of the spark plug designated to be fired via means of a mechanical linkage between the engine camshaft and the rotor; and (2) a contactless ignition system which uses an electronic controller to analyze the signal generated by a sensor in order to determine the correct firing sequence of the spark plugs.
The first type of conventional system has presented numerous problems related to (a) the minimum size of the distributor required to provide the amount of high voltage insulation necessary to prevent misfiring of the spark plugs, to (b) the limits placed upon the physical location of the distributor which must be mechanically linked to the engine camshaft, to (c) the relatively high cost of providing the required mechanical link to the engine camshaft, to (d) the extremely high amount of service and maintenance that is required to keep the system operating within acceptable tolerance levels.
The second type of contactless ignition system was designed to correct the known problems with the first type and typically utilizes either multiple ignition coils or a single coil with multiple inputs and outputs to provide the high voltage spark necessary to fire the spark plugs. An electronic controller which receives a signal from a sensor which detects movement of the engine camshaft, analyzes the signal and determines the proper firing sequence for each of the spark plugs. The requirements of multiple ignition coils or coils with multiple inputs and outputs, and of needing a complex controller to analyze the signals and determine the proper firing sequence, result in high manufacturing costs. Additionally, each spark plug must be fired on both the compression and exhaust cycles, thus causing a decrease in the service life of the spark plugs which in turn increases the maintenance costs of this type of contactless ignition system.